[-cxx-abi microsoft] Mangle __uuidof correctly into template parameters

Summary:
It seems that __uuidof introduces a global extern "C" declaration of
type __s_GUID.  However, our implementation of __uuidof does not provide
such a declaration and thus must open-code the mangling for __uuidof in
template parameters.

This allows us to codegen scoped COM pointers and other such things.

This fixes PR16836.
Depends on D1356.

Reviewers: rnk, cdavis5x, rsmith

Reviewed By: rnk

CC: cfe-commits

Differential Revision: http://llvm-reviews.chandlerc.com/D1357

llvm-svn: 188252

1 files changed, 15 insertions, 0 deletions

diff --git a/clang/lib/AST/ExprCXX.cpp b/clang/lib/AST/ExprCXX.cpp
index 496697fc55b..055fc3b8142 100644
--- a/clang/lib/AST/ExprCXX.cpp
+++ b/clang/lib/AST/ExprCXX.cpp
@@ -72,6 +72,21 @@ UuidAttr *CXXUuidofExpr::GetUuidAttrOfType(QualType QT) {
   return 0;
 }
 
+StringRef CXXUuidofExpr::getUuidAsStringRef(ASTContext &Context) const {
+  StringRef Uuid;
+  if (isTypeOperand())
+    Uuid = CXXUuidofExpr::GetUuidAttrOfType(getTypeOperand())->getGuid();
+  else {
+    // Special case: __uuidof(0) means an all-zero GUID.
+    Expr *Op = getExprOperand();
+    if (!Op->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull))
+      Uuid = CXXUuidofExpr::GetUuidAttrOfType(Op->getType())->getGuid();
+    else
+      Uuid = "00000000-0000-0000-0000-000000000000";
+  }
+  return Uuid;
+}
+
 // CXXScalarValueInitExpr
 SourceLocation CXXScalarValueInitExpr::getLocStart() const {
   return TypeInfo ? TypeInfo->getTypeLoc().getBeginLoc() : RParenLoc;